Shell's tension leg platform named Olympus, left, and Chevron's tension leg platform named Big Foot, second from right, and semi-submersible platform named Jack / St Malo, right, are shown under construction at ... more

The Royal Dutch Shell Plc Olympus tension leg platform (TLP) is seen at night as it sets sail from Kiewit Offshore Services in Ingleside, Texas, U.S., on Saturday, July 13, 2013. Olympus, Shell's biggest constructed tension leg platform, started the ten day, 425-mile voyage to Mars B Field in the Gulf of Mexico on July 13. Photographer: Eddie Seal/Bloomberg less

The Royal Dutch Shell Plc Olympus tension leg platform (TLP) is seen at night as it sets sail from Kiewit Offshore Services in Ingleside, Texas, U.S., on Saturday, July 13, 2013. Olympus, Shell's biggest ... more

The topside production module of the Anadarko Petroleum Corporation's Lucius truss spar is shown under construction at Kiewit Offshore Services, 2440 Kiewit Road, Thursday, July 11, 2013, in Ingleside. It is the largest spar built to date by Anadarko. ( Melissa Phillip / Houston Chronicle ) less

The topside production module of the Anadarko Petroleum Corporation's Lucius truss spar is shown under construction at Kiewit Offshore Services, 2440 Kiewit Road, Thursday, July 11, 2013, in Ingleside. It is ... more

Photo: Melissa Phillip, Houston Chronicle

The topside production module of the Anadarko Petroleum... Photo-4942498.66759 - NewsTimes

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People walk by the topside production module of the Anadarko Petroleum Corporation's Lucius truss spar shown under construction at Kiewit Offshore Services, 2440 Kiewit Road, work on the Thursday, July 11, 2013, in Ingleside. ( Melissa Phillip / Houston Chronicle ) less

People walk by the topside production module of the Anadarko Petroleum Corporation's Lucius truss spar shown under construction at Kiewit Offshore Services, 2440 Kiewit Road, work on the Thursday, July 11, ... more

Photo: Melissa Phillip, Houston Chronicle

People walk by the topside production module of the Anadarko... Photo-4942499.66759 - NewsTimes

Image 6 of 9

Tugboats are shown beside the Anadarko Petroleum Corporation's Lucius truss spar at Kiewit Offshore Services, 2440 Kiewit Road, Thursday, July 11, 2013, in Ingleside. It is the largest spar built to date by Anadarko. The diameter of the spar is 110 feet and the length is 605 feet. Shown at right is Chevron's tension leg platform named Big Foot. ( Melissa Phillip / Houston Chronicle ) less

Tugboats are shown beside the Anadarko Petroleum Corporation's Lucius truss spar at Kiewit Offshore Services, 2440 Kiewit Road, Thursday, July 11, 2013, in Ingleside. It is the largest spar built to date by ... more

Tugboats are shown beside the Anadarko Petroleum Corporation's Lucius truss spar at Kiewit Offshore Services, 2440 Kiewit Road, Thursday, July 11, 2013, in Ingleside. It is the largest spar built to date by Anadarko. The diameter of the spar is 110 feet and the length is 605 feet. Shown on left is Shell's tension leg platform named Olympus. ( Melissa Phillip / Houston Chronicle ) less

Tugboats are shown beside the Anadarko Petroleum Corporation's Lucius truss spar at Kiewit Offshore Services, 2440 Kiewit Road, Thursday, July 11, 2013, in Ingleside. It is the largest spar built to date by ... more